Take-up mechanism for circular knitting machine



De@ 22, 1964 J. N. LANCASTER ETAL 3,162,392

TAKE-UP MECHANISM FOR CIRCULAR KNITTING MACHINE Filed Feb. 4, 1963 INVENTORS A dfi/vas /K fw/rows rf@ BY CMQ/fz E5 /f Po/ypf/P a-Wwf Mm United States Patent Oiitice arrasar Patented Dec. 22, 1964 3,162,392 TAKE-UP MECHANISM FUR CIRCULAR KNIT'IENG MACHINE James N. Lancaster, E. Main St., Stoneville, NC., and

Charles H. londer, 2807 Northampton Drive, Greensboro, N.C.

Filed Feb. 4, 1963, SeruNo. 255,887 6 Claims. (Cl. 242-66) The present invention relates to peripherally driven take-up rolls for knitting machines, especially circular knitting machines. The principal objects are to provide means for turning a take-up roll and to increase the tightness and compactness of the fabric on the roll, particularly in the later stages of a knitting run, and thereby to increase the continuous length of fabric which can be knit without interruption.

Circular knitting machines produce a tubular fabric which commonly is drawn upwardly from the needle cylinder or down through the cylinder, pressed hat and wound on a take-up roll, Generally, the rolls are equipped to handle relatively short continuous lengths `of fabric, and, when this length has been knit, it is necessary to interrupt the knitting operation. For example, for fabrics knit from twisted paper yarn, the longest continuous length which can be made is about 100 yards. For many purposes, it is essentional to have fabrics of greater length, such las 200400 yards or more.

In a sense, larger take-up rolls-are possible and it might seem that increasing the size of the rolls might be all that is required. However, there are basic limitations on the take-up mechanisms now in use which renders them unsuitable for long lengths of fabrics, even if they are increased in size.

" A take-up mechanism of particular interest includes a large take-up roll 'on which the attened tube of fabric is wound and a pair of squeeze or draw rolls, one above the other, which atten the fabric as it passes between them. The upper draw roll peripherally engages the take-up roll and turns it. That is, the take-up roll itself is not driven directly but indirectly by the upper draw roll. The lower draw roll also may be driven by peripheral engagement with the upper draw roll. It will be appreciated that this arrangement assures that linear speeds of the peripheries of the rolls are the same The shaft of the take-up roll is mounted in vertical guides which permit it to move upwardly and downwardly. This provides for raising the shaft of the take-up roll to increase the distance between it and the upper draw roll to accommodate the fabric. As the amount of fabric increases, the angle 'of contact between the upper draw roll and the fabric on` the take-up roll changes, and this is believed to reduce the ability of the draw roll to drive the take-up roll. Of course, this takes place as the driving force required increases because of the growing weight of fabric on the roll.

In addition, the fabric wound on the take-up roll in the later stages of a knitting run tends to be wound more loosely. This is believed to be caused by the necessity of the draw roll to support the weight of the take-up roll. As lthe weight of the fabric on the take-up roll increases, the draw roll must push harder to turn it and this forward pushing is applied to the take-up roll y, just as the fabric is being laid on, which is believed to loosen the fabric on the roll. Consequently, the tightness of the fabric decreases from the inside of the roll to the outside and is non-uniform.

The present invention provides an improvement which avoids these diiculties. Briefly stated, an additional driving roller is provided near the fabric take-up roll which supplies additional peripheral driving power to the roll only after a substantial length of fabric has already been wound. The auxiliary drive roll engages the takeup roll shortly in advance of the upper draw roll. Preferably, the auxiliary roll also is turned slightly faster than the upper draw roll and has a smoother surface.

The invention will be illustrated by the following detailed description of a preferred embodiment, using a spring needle knitting machine and with reference to the drawing in which:

FIGURE l is an elevation of the upper part of a spring needle type knitting machine incorporating the present invention;

FIGURE 2 is a section along line 2 2 of FIGURE l; and

FIGURE 3 is a section along line 3 3 of FIGURE l.

The spring needle knitting machine shown in the draw ings is of the general type described in US. VPatent 2,329,618 of W. A. Ingalls and the copending application of Robert Grey Egerton and I ames N. Lancaster for a knitting machine tiled on January 7, 1963. Accordingly, only the take-up mechanism will be described in detail.

The take-up mechanism includes a take-up roll 1, upper draw roll 2, lower draw roll 3, and auxiliary drive roll 4. The four rolls are mounted for rotation within an inverted U-shaped carriage 5 above the needle cylinder and which turns in synchronism with the needle cylinder.

There is a horizontal circular track 6 supported by upright posts of the frame 7 of the machine and the lower ends of the carriage for wheels which ride in the track. As the machine operates, the carriage turns on the track.

Above the carriage are two horizontal arms 8 and S of the frame which extend toward the center of the machine from upright posts and a horizontal plate 9 is suspended between them. There is a vertical opening 10 through the plate above the center of the carriage and a shaft 11 is journalled in it and welded to the top of the carriage. Near its top, above theplate 9, the shaft carries a bevelled gear 12. There is a D C. motor 13 on top or" the frame 7 near the shaft which drives it through a drive shaft 14 and a bevelled gear 15 which meshes with gear 12. The D.C. motor is synchronized by suitable conventional means with the needle cylinder drive.

The sides of the carriage are provided with suitably positioned bearings for the shafts of the rolls l, 2, 3 and 4. The rolls 1, 2 and 3 are substantially in line, one above the other, rolls 2 and 3 being in xed position. The bearings for the take-up roll 3 are slidably movable in vertical directions and vertical guides are suitably provided in the carriage for this purpose.

The auxiliary drive roll 4 is positioned outwardly from the draw rolls and slightly above the upper draw roll. In this position, it does not engage the fabric on the takeup roll initially. Thus, during the early stages of a knitting run, only an upper draw roll is in contact with the take-up roll but, as the run continues, the diameter of the take-up roll, including the fabric wound on, Vincreases. Then, when the auxiliary roll iirst comes in contact with the take-up roll, the contact pressure is relatively light, but it increases as morefabric is wound on in which: l

a=distance between axes oftake-upfroll and auxiliary roll b=distance between vaxes of take-up roll and upper draw roll c=distance between axes of auxiliary roll and 'upper draw roll v 1 A=angle between a line connecting the take-up roll axis with the upper draw -roll axis and a line connecting the auxiliary roll axis with the upper draw roll axis.

in which:

t1=radia1 thickness (1/2k of overall thickness) of upper draw roll t2=radial thickness of take-up roll (including core and fabric).

The condition for contact between the auxiliary roll and the take-up roll is given by (3) Uffa-Ffa in which:

t3=radial thickness of auxiliary roll Ofcourse, 'the above relations are somewhat lacking in precision because the softness of the rolls, particularly of the fabric on the take-.up roll, causes the, rolls to press. 1

into each other but the relations may be used as an approximate guide in setting the rolls. It is preferable to provide for adjustments of positions of the rolls so that the time when the auxiliary roll first contacts the take-up roll can be regulated.

Typically, for a knitting machine of the. above' type, each of the rolls 11, 2, 3-and 4 will be of .Z-inch diameter. The auxiliaryjdrive roll is positioned about 3 inches out from the upper draw roll and a short'distance, say 1 to 11/2 inches aboveit. vThe auxiliary roll then does not come in contact with the fabric lon the take-up r'olll until the diameter of the takeaup roll is about 16'inches vand then will remain in contact until the end of a run when the diameter increases to about 32'33 inches.

The mountingsV for the auxiliary drive roll may be of any simple structure such as brackets 15 Vfixed tothe sides of the carriage as shown yin the drawing. These carry .bearings in which the shaft` of the roll is journalled.

drive Ashaft 18 extending from the center of the carriage to theouter edge above crank 17, and journalled in suitable bearings 19 and 20. At the outer end of this drive shaft, there is another crank 21, and apitman 22 connects cranks 17 and 21. At the inner end of the drive shaft 18, there is a bevelled gear 23. The plate 9 has a dependingshank 24. There is a stationary ring gear 25 around the lower end of shank24 which meshes with bevelled gear 23. Consequently, as the carriage rotates, the drive shaft 18 is turned and the upper. draw roll is turned through cranks 17 and 21 and the pitman 22.

A chain drive 26is provided for the auxiliary drive roll. This includes a sprocket wheel 27 on the shaft of upper draw roll 2,.a sprocket wheel 281on lthe shaft of the auxiliary drive-roll 4 and a chain trained around the sprocket wheels. The 'sprocket wheel .28'I is of somewhat smaller diameter than the'sprocket wheel V27 and has fewer teeth. For example, wheel 27 may have 25 teeth andwheel 28 may have 24 teeth. This causes the auxiliary driveroll to turn slightly faster than the upper draw roll 2..

The rolls 2, 3 and 4fare Acovered with materials vto give suitable friction characteristics with the fabric. Forexample, in the case of fabricsjknit from twistedpaper yarn, thedraw rolls 2 and 3 may have sandpaper covering.l Theauxiliary'drive roll 4 is preferably smoother and might be covered with a finer grade of sandpaper so that Vit slips slightly against the fabric to compensate for the difference between its speed and that of the upper draw roll. This `causes a tightening of the fabric on ythe roll, in addition to the aid which Vthe yauxiliary drive roll gives in turning* the heavy roll of fabric.

The invention has now been described by reference to la preferred embodiment whchis illustratedin the drawings. However, Ait will be appreciated that Various changes and modifications maybe madein the details of construction and the mode `of operation without departing from the scope of the invention, as this isset out in the claims.

l What is claimed is: i

' l. A take-up mechanism .for circular knitting machines comprising a draw roll, means for turning said draw roll about its axis, a take-up roll forvaccumulating fabric in' a readily compressible roll, means for mountngthe ends of said take-up roll with the axis of said take-up roll parallelto the-axisof Asaid draw roll, forrotation about its axis, an d for movement towardfandqaway from said draw f roll, said'take-uproll being urged toward said draw roll to peripherally and frictionally engage -the draw roll and be turned by it,` an auxiliary drive roll, means for mounting saidV auxiliary drive roll -with its axis parallel` to Athat of said draw'roll but spaced from a line connectingthe i Vaxes of said draw roll and saidtakevup roll, the respective axes of said rolls ybeing .positioned at thecorners of 'a triangle, and said auxiliary drive roll being in position ,to

peripherally engage and 'radially lcompress the Yfabric acf cumulated on said take-up roll only after a predetermined minimum of fabric has accumulated, and means for turn- ,Y ingsaid auxiliary drive roll `about, Vits axis, whereby said 'The auxiliary roll has a center shaft16 which is journalled f;

in; the bearings.

However, the auxiliary roll may bef journalled in bearings in supportarms pivotally mountedl on the sidesv of the carriage 5 to facilitate adjustment. It is also possible to mount the axiliary drive rolls for movement in guides toward and away from the take-up roll against fairly strong springs so that the auxiliary drive roll will have better controlled pressure against the take-up roll. It should be noted rthat the auxiliary drive roll contacts the downwardly moving side of the take-up roll.

The upper draw roll 2'isY driven by a crank mechanism.r` The shaft of f the roll 2 carries at its outer end a crank,

17I At the. top 0f the carriage 5 there isy a horizontal auxiliaryrdrive roll aids in the yturn'ingof Vsaid take-up rolly by peripherally engaging 'it-only after apart of the fabric hasbeen Wound on saidrtake-up rolle" 2. A ytake-'up mechanism for circular 'knitting machines;

asset forth in claim lin-which the take-uproll Yis `above the draw roll and Vis urged toward and against `the draw roll by gravity. f Y f 3 5- A take-up mechanism for circular knitting' machines as seft forth in Vclaim 2 including a lsecond draw `roll rotatably mounted below the first draw roll with its axis parallel to the axis of the first draw `roll and peripherally engaging said irst draw rol1. -v Y 4; A- take-up mechanism for circular knitting machines above .and .to one side of the draw roll.

5. A take-up mechanism for circular knitting machines asset forth in claim 1 in whichsaid means Yfor'turning Vas set forth in claim 22 in which `the lauxiliary drive roll is 5 said auxiliary drive roll is synchronized with said means iliary drive roll is smoother than the surface of said draw for turning said draw roll and is constructed and arroll. ranged to turn said auxiliary drive roll at a higher periph- References Cited in the le of this patent eral speed than said draw roll. UNITED STATES PATENTS 6. AA takeup mechanism for circular knitting machines 5 2,461,387 Medbery Feb. 8 1949 as set forth 1n claim 5 1n which the surface of said aux- 3,047,248 Birch et aL July 31 1962 

1. A TAKE-UP MECHANISM FOR CIRCULAR KNITTING MACHINES COMPRISING A DRAW ROLL, MEANS FOR TURNING SAID DRAW ROLL ABOUT ITS AXIS, A TAKE-UP ROLL FOR ACCUMULATING READILY COMPRESSIBLE ROLL, MEANS FOR MOUNTING THE ENDS OF SAID TAKE-UP ROLL WITH THE AXIS OF SAID TAKE-UP ROLL PARALLEL TO THE AXIS OF SAID DRAW ROLL, FOR ROTATION ABOUT ITS AXIS, AND FOR MOVEMENT TOWARD AND AWAY FROM SAID DRAW ROLL, SAID TAKE-UP ROLL BEING URGED TOWARD SAID DRAW ROLL TO PERIPHERALLY AND FRICTIONALLY ENGAGE THE DRAW ROLL AND BE TURNED BY IT, AN AUXILIARY DRIVE ROLL, MEANS FOR MOUNTING SAID AUXILIARY DRIVE ROLL WITH ITS AXIS PARALLEL TO THAT OF SAID DRAW ROLL BUT SPACED FROM A LINE CONNECTING THE AXES OF SAID DRAW ROLL AND SAID TAKE-UP ROLL, THE RESPECTIVE AXES OF SAID ROLLS BEING POSITIONED AT THE CORNERS OF A TRIANGLE, AND SAID AUXILIARY DRIVE ROLL BEING IN POSITION TO PERIPHERALLY ENGAGE AND RADIALLY COMPRESS THE FABRIC AC- 